Transfusion Reactions

Question 1

Describe processing of blood components?

Answer 1

centrifuged into separate component parts
test for hiv, hep b, hep c, hep e, HTLV, syphilis
red cells are stored at 4 degrees for 35 days
FFP at 30 degrees for 3 years
platelets at 22 degrees for 7 days

Question 2

What blood component has biggest risk of infection/ contamination?

Answer 2

platelets because they are stored at room temperature

Question 3

Describe donor products available?

Answer 3

from one donor:
red cells
FFP (source of clotting factors)
cryoprecipitate (concentrated source of fibrinogen and some clotting factors)
platelets

pooled from many donors:
human albumin
anti D
anti VZV
IV Ig

Question 4

What are the most important blood groups?

Answer 4

there are over 30 blood groups in total but ABO (landsteiners law) and rhesus (very immunogenic) are most important

Question 5

Explain the significance of ABO and Landsteiner’s law?

Answer 5

when an individual lacks the A or B antigen they will have the antibody present (due to natural exposure though food and bacteria)
this means you can have a massive transfusion reaction on your first transfusion

Question 6

Explain the significance of the Rh system?

Answer 6

85% of the population are rhesus positive
person can be exposed to RhD antigen through pregnancy or transfusion
then could cause reactions or haemolytic disease of newborn
tend to avoid exposing rhesus negative people to rhesus positive

Question 7

When may other blood groups cause a problem?

Answer 7

in those who have had lots of transfusions (more likely to have formed alloantibodies)

Question 8

Describe pre-transfusion testing?

Answer 8

identify ABO and Rh status of individual and look for any other clinically relevant antibodies
look for antibodies by testing for agglutination
with other blood groups this is done with multiple reagents at once and only if positive would test further

Question 9

Overview of types of transfusion reaction?

Answer 9

immune:
AHTR
DHTR
Mild reactions: febrile non haemolytic transfusion reaction and mild allergic reaction
anaphylactic reaction
TRALI

non immune:
viral contamination
bacterial contamination
TACO

Question 10

Overview of algorithm for acute transfusion reaction?

Answer 10

In everyone - stop the transfusion
assess using ABCDE - is the patient well or unwell?
recheck compatibility and assess the pack for contamination
document event in notes

If patient is well:
Urticaria - give an antihistamine and continue transfusion at a slower rate
Isolated temperature rise: give paracetamol and continue transfusion at a slower rate

If the patient is unwell:
Consider
Anaphylaxis
ABO incompatibility
bacterial contamination

Question 11

AHTR is due to?

Answer 11

ABO incompatibility
IgM antibodies, massive complement activation

Question 12

Presentation of AHTR?

Answer 12

rigors, lumbar pain, lumbar pain, renal failure, hypotension, haemoglobinuria

Question 13

Management of AHTR?

Answer 13

inform lab, repeat samples, bloods (FBCs, coag, UEs, LFTs), blood cultures, supportive measures, Hartmanns fluid bolus, contact consultant haematologist

Question 14

DHTR is due to?

Answer 14

IgG alloantibodies from pregnancy or previous transfusion

Question 15

Presentation of DHTR?

Answer 15

extravascular haemolytic 5-10 days post reaction
alloantibodies detectable at this time but levels were too low pre-transfusion
anaemic and jaundiced

Question 16

Describe 2 mild transfusion reactions and management?

Answer 16

temp rise or a rash

Febrile non haemolytic transfusion reaction - HLA antibodies - paracetamol and continue transfusion

mild allergic reaction - plasma components - antihistamine and continue transfusion

Question 17

Describe bacterial transmission as a transfusion reaction?

Answer 17

rare but most frequent cause of death associated with transfusions
more common with platelets stored at 22 degrees
management - culture patient sample and remains of unit, broad spectrum antibiotics, inform lab so other samples can be quarantined

Question 18

Explain what TACO is?

Answer 18

pulmonary oedema that develops due to circulatory overload

Question 19

Risk factors for TACO?

Answer 19

elderly patients, cardiac failure, low albumin, renal failure, fluid overloaded

Question 20

Presentation of TACO?

Answer 20

respiratory distress within 6 hours of transfusion
raised JVP
raised BP
positive fluid balance
crackles on auscultation

Question 21

Management and prevention of TACO?

Answer 21

management: oxygen and supportive care, diuretics
prevention: consider slowing rates of further transfusions, aim to identify patients at risk before first transfusion

Question 22

Describe an anaphylactic transfusion reaction?

Answer 22

presents within 1-45 minutes of reaction
increased risk in those who are IgA deficient
presents with hypotension, wheezing, dyspnoea, angioedema
stop transfusion, IM adrenaline (500 micrograms for an adult), ABCDE

Question 23

Explain what TRALI is?

Answer 23

non cariogenic PO thought to be secondary to increased vascular permeability by host neutrophils that become activated by substances in donated blood

Question 24

Presentation of TRALI vs TACO?

Answer 24

TACO:
hypertension
raised JVP
afebrile
S3 present

TRALI:
hypotension
pyrexia
normal/ unchanged JVP

Question 25

What can be used to confirm haemolysis?

Answer 25

Coombs test, unconjugated bilirubin, haptoglobin, serum and urine free haemoglobin

Question 26

Major components of cryoprecipitate?

Answer 26

factor 8 and fibrinogen

Question 27

Offer platelet transfusion to?

Answer 27

those with platelet count less than 30 and active bleeding

Question 28

Low or high haptoglobin is suggestive of haemolysis?

Answer 28

low haptoglobin is suggestive of haemolysis
this is because haptoglobin binds free haemoglobin and if there is more haemolysis there is more free haemoglobin so haptoglobin is used up